As one of the measures for increasing the capacity of a memory LSI, such as a flash memory or a DRAM (dynamic random access memory), a variety of memory module structures, which are manufactured by stacking semiconductor chips, each having such a memory LSI formed thereon, and then sealing them in a single package, have been proposed.
For example, Japanese Patent Application Laid-Open No. Hei 4(1992)-302164 discloses a package structure obtained by stacking, stepwise, in one package, a plurality of semiconductor chips having the same function and the same size via an insulating layer, and electrically connecting a bonding pad which is exposed at the stepped portion of each of the semiconductor chips with an inner lead of the package through a wire.
Japanese Patent Application Laid-Open No. Hei 11 (1999)-204720 discloses a package structure manufactured by loading a first semiconductor chip on an insulating substrate via a thermocompressive sheet, loading on the first semiconductor chip a second semiconductor chip which is smaller in external size than the first semiconductor chip via another thermocompressive sheet, electrically connecting each of the bonding pads of the first and second semiconductor chips with an interconnect layer on the insulating substrate via a wire, and then resin-sealing the first and second semiconductor chips and the wire.